How We Got to Understand Tornadoes

Rob Hardy

May 4, 2013 11:19:53 AM

I like the Weather Channel because of its local weather reports ("Local on the Eights"). There is only so much you can do with 24-hour weather, though, and I will not watch the channel's bloated programming about Coast Guard rescues, cowboys who fix wind turbines, or, for goodness sakes, people who prospect for minerals. If there is a video of storm chasers pursing a tornado, though, that gets my attention. One such storm chaser played down the risk connected to his hobby. "The biggest risk," he said, "is that you will get rear-ended by the chaser behind you." A version of that joke is included in Storm Kings: The Untold Story of America's First Tornado Chasers (Pantheon Books) by Lee Sandlin. Tornadoes do happen other places in the world, Sandlin explains, but the flat plains of the US breed them like nowhere else. Many of the chasers described in this history were in what we would consider slow motion, not in hot pursuit of funnel clouds but roaming the country to get data from storms gone by and to get some understanding of what these strange American winds were. The investigators were quirky, wrongheaded, inspired, and intolerant of meteorological opinions other than their own; in short, they were curious and flawed human beings trying to understand one of nature's most violent productions. It is a great human story, and Sandlin tells it with humor and warmth.

American Indians, of course, knew about tornadoes, and told stories about them. The settlers coming from Europe pushed into the plains and witnessed the huge storms. It was not until the mid-1700s that settlers realized that tornadoes were something distinct from the usual barrage of wind, lightning, and rain. One of the first to realize that something unusual was going on was none other than Ben Franklin, who might just be, with all his other accolades, the first storm chaser ever. In the spring of 1754, he spied a whirlwind in Maryland. Those with him held back, but he urged his horse to a trot, and began a pursuit while the whirlwind was relatively small. He knew that sailors had supposedly broken up waterspouts by firing cannons at them, and he tried lashing the whirlwind with his whip. Nothing happened. He wrote, "The progressive motion of the whirl was not so swift but that a man on foot might have kept pace with it, but the circular motion was amazingly rapid." He started getting worried when the wind began to pick up large boughs and take them aloft, but eventually the storm drifted off and died away. Franklin wrote to the Royal Society in London his opinion that these were a particular type of storm, upward-rushing columns of rotating air. His page illustrating such a column, reproduced here, also has one of Franklin's magic squares included.

After that, things got confusing. A former schoolteacher in Kentucky, James Espy, in the 1830s agreed with Franklin that the tornado was a rising column of air, and understood that it was heated and drawn up by convection. But he insisted that the air arose in a perfectly straight line. There were eyewitnesses who said that the wind was funnel-shaped and rapidly rotating, but Espy explained that such witnesses were simply mistaken. He also thought that people suffering from a drought could initiate storms by getting the air rising in the first place by setting huge fires, a pet project of his that never came to pass. In June 1835, a killer tornado struck in New Jersey, and Espy, along with college professors and amateur weather enthusiasts, came afterwards, documenting the damage and looking up and down the path that the storm had taken; it was the basic way to get data about a tornado. Espy had a talent for making himself known and for disputation. In an era when people enjoyed public debates, and when scientists, or scientist-pretenders, would attempt to settle issues by debating (rather than publishing data and theories to explain it), he proclaimed that straight rising air had done all the damage. He was probably gratified when William Redfield, the owner of a steamboat company who had a great interest in what the weather might do, insisted that the huge winds were the same as the harmless rotating whirlwinds, only bigger, and that the rotating winds had done the damage. The public loved the debates, which were carried out in person and in print. Espy was hired by the Smithsonian to cover weather, and might be considered our nation's first meteorologist.

By the middle of the nineteenth century, most weather researchers understood that tornadoes rotated, but explanations about the meteorological physics of tornadoes were long in coming. Almost no books about tornadoes were published from around 1880 until 1940. One must consider The Wonderful Wizard of Oz of 1900 which has a famous tornado. Sandlin says that Baum may have known about the competing ideas of tornado genesis at the time, but that he had never seen a tornado and had no idea how a tornado behaved. Baum explained that the pressure on Dorothy's house on every side raised it up to the top of the storm. Baum's "throwaway description" of a tornado is feeble compared to the fearful storm as depicted in the movie The Wizard of Oz. The house, with Dorothy and Toto in it, gets lifted whole as in the book, but there was a believable recreation of a tornado, even though it was merely a big sock in the studio, filled with fuller's earth to make a little dust storm around its base.

It might seem surprising that the Army Signal Corp, created to secure good communication on the battlefield, should have a role in weather research and even weather reporting. Much of Sandlin's story is about bureaucracies that wanted to be the national weather department, and how the Army lost out to an eventual civilian national weather service. (Remarkably, because of the prickly personalities involved, the story does not flag during these pages.) One of the characters profiled here is Army Signal Corpsman John Park Finley. In the 1880's Finley trekked across America to get to tornado sites to take data firsthand, and he reviewed a century of written accounts by people who had been through the storms. He interviewed people who had experienced tornadoes, and all wanted to make sure he had their stories. While he was on the road, he collected copies of tornado reports at weather stations, and he gave talks about tornadoes and the Signal Corps, always enlisting volunteers to become "tornado reporters." It all helped him confirm that colliding air masses over the broad plains were the cause of tornadoes. The great goal was to be able to predict when and where a tornado might occur, and he had fame for doing so with some statistical success, but his warnings took in too broad swaths of territory to be truly helpful.

We are a little better at predicting tornadoes now, but no one who lives in tornado country needs to be told that our tornado watches and warnings involve plenty of false alarms. The system grew out of guidelines suggested to the Weather Bureau in the 1950s by Robert C. Miller, who, along with E. J. Fawbush, had been a forecaster for the Air Force, an organization that valued weather prediction for obvious reasons. In 1948, a tornado swept through Tinker Air Force Base in Oklahoma and damaged plenty of equipment. Five days later, Miller and Fawbush, meteorologists at Tinker, recognized that the same sort of weather pattern had formed over the region again. Miller had some uncanny ability to visualize storms in all dimensions. Under pressure, the pair issued a warning, an alert was sounded, and equipment and buildings were secured in time before the tornado touched down just as they predicted. They were heroes, although neither they nor anyone else has ever had this sort of pinpoint success again. Stories flew that the military had a super-secret way of predicting tornadoes, and it was not going to help civilians by divulging it.

Sandlin's dynamic account winds up with the invaluable tool of Doppler radar, and the investigations by Japanese-American meteorologist Tetsuya Fujita, who modeled tornadoes from generation through destructive storm to decay. Fujita also invented a scale of destructive power for the storms, F1 to F5, still in common use. We do know more about the storms, through the persistence of men like the ones whose stories are told here. The strange lights, for instance, that people used to see around funnels have never been recorded on the many videos of tornadoes, and seem to have been imaginary. Tornadoes also do not skip over the ground as they move; once it is stirring up trouble on the ground, a tornado is there until it dies out. Also, advice that was given sagely for generations has been shown to be simply false: houses do not explode because of a pressure buildup when tornadoes come through. They simply blow apart from the high winds, and opening the windows to "equalize" the air pressure is useless. Sandlin quotes the experts: "Don't bother opening the windows. The tornado will do that for you." It's a bit of practical lore from an agreeable and amusing book full of social and meteorological American history.